This invention relates generally to a squeeze bottle powder dispenser, and more particularly to such a dispenser having a dip tube through which the powder is discharged upon alternately squeezing and releasing the squeeze bottle, the dip tube having at its inner end an attached pad of open cellular foam material for moderating the flow of powder to effect a smooth and uniform flow of powder through the tube without clogging or agglomeration during dispensing.
It is frequently necessary or desirable to administer or apply active medicinal agents in powder form. Some medicinals are so unstable (e.g. antibiotics) that dry powder sprays are the best way to apply them to the skin especially onto wet body surfaces or to administer them intranasally or by oral inhalation into the lungs or into other body cavities.
In some cases it is most desirable to administer the active agent in powder form for aesthetic reasons as, for example, in the case of underarm antiperspirants. The active antiperspirant chemicals are all powders and the other ingredients used to formulate the typical product forms reduce the activity of the antiperspirants and leave some objectionable residues in the underarm areas. The history of product developments in the field of antiperspirants suggests that dryness is the key product attribute most appreciated by consumers. Yet the existing product forms, roll-ons, aerosols and sticks, leave some significant residue other than the active agent on the skin of the underarm. Consumers universally object to these residues considering their presence in contrast to the desired dryness they hope to achieve.
Additionally, powders administered as sprays intranasally or by oral inhalation provide a preferred route for the systemic action of some medicinal agents. Many drugs can enter the blood stream rapidly through the oral and nasal mucosa and proceed rapidly to the site of their action in the body. In this manner the destructive effect of the gastrointestinal tract upon the drug's integrity is avoided and also avoided is the irritant effect of many drugs upon the stomach and intestines.
It has therefore been long recognized that powder sprays have unique advantages. Yet the devices for the administration of powders developed in the past have been cumbersome, complicated and expensive, inconvenient or unpleasant to use. For example, U.S. Pat. No. 2,840,277 discloses a squeeze bottle powder dispenser having a dip tube through which the powder is discharged upon squeezing the bottle. Other powder dispensers, known as insufflators, provide a squeeze bulb for directing air under pressure into a powder container creating an air turbulence which mixes air into the powder causing the mixture to be discharged through a discharge spout. However, these devices are incapable of delivering a uniform spray of powder so that consistent dosage can be obtained. These disadvantages have therefore limited the use of powder sprays as a means of delivering active ingredients to the human body.